1. Field of the Invention
This invention relates to a novel and improved apparatus and method for controllably and accurately distributing a selected density of granular material on to the surface of an article. In particular, this invention relates to an apparatus and distributor for coating an article of food with a granular food product at selected density. This invention has utility for a wide variety of applications. Any granular material of selected size can be distributed on a surface at a controlled weight. One application, but not necessarily the only such application, is for coating a granular food product onto an article of food; for example, coating shredded cheese, meat pieces or the like onto pizza shells or other such food article.
2. Description of the Prior Art
It is known in the prior art to utilize apparatus for distributing granular food material onto the surface of an article of food. One known granular food material spreader utilizes a separate lower hopper for storing or enclosing a shredded food material and an elevator conveyor for transporting the granular food material to a separate elevated hopper. Each hopper has an agitating system to prevent the granular food material from forming masses or clusters of food material. Photocell control system detect and control quantity levels of granular material in each hopper. A pin drum located at the bottom of the elevated hopper is rotated at a controlled variable speed to feed a continuous flow of granular material to the food article being coated. Excess product is reclaimed and returned to the lower hopper for recirculation.
Another known prior art device utilizes a vertically mounted, funnel shaped hopper assembly for distributing free flowing granular material such as bread crumbs, spices, etc. The orifice end of the funnel communicates with a conical-shaped nozzle which directs the granular material into a substantially uniform stream. A single vertically mounted auger extends from the orifice vertically into the center of the hopper and is rotatable therein to deliver free flowing material through the hopper orifice, into the nozzle and out of the assembly in a controlled directed stream. Such assembly has utility for filling container or the like with granular food material.
Other known food distributing apparatus utilize a horizontally pivotally mounted disc member which functions as a continuous motion filler to receive and convey food, such as blanched or frozen carrots, peas, beans or the like, from a hopper to a food line for packaging.
Another known device is similar in assembly but utilizes a pivotally mounted rotatable disc member to spread the granular material received from the hopper in a circular pattern onto a surface.
Certain known mixers and blenders utilize a pair of contrarotatable controlled speed augers to mix or blend food and transport the so blended food out of a mixing cavity through an orifice formed in the mixing cavity.
The known prior art devices have certain disadvantages. For example, the two hopper, pin drum distributor system results in the granular material being subjected to storage away from the actual distributing area and transportation of controlled quantities by a photocell control system to the actual distributing area. Further, it appears that the pin drum is positioned under the opening in the elevated hopper resulting in the metering of the granular material by deposition onto the pin drum surface and rotation of the material to the tangential point where the material falls off of the drum onto the article. The granular food material weight or density is controllable substantially by speed of drum rotation. The size, quantity and type of granular food material must be compatible with opening size, the spacing of the fixed rotatable drum below the opening and size and spacing of pins on the drum surface.
The vertically mounted hopper assembly is limited in application. Distribution of granular food material is in a substantial stream-like flow which generally cannot be used to coat granular material uniformly on the surface of an article of food.
Continuous motion fillers utilizing rotatable horizontally pivotally mounted disc members are generally limited in application to food fillers; that is, for depositing a metered volume of food in a package, tray or the like.
Similarly, spreaders or distributors having a conical shaped hopper terminating in a rotatable pivotally mounted disc member distribute granular material in generally uncontrollable density in a circular pattern. Controlled even densities are difficult to obtain and precisely control.
The known mixers and blender having contra-rotatable augers have a mixing cavity into which food ingredients to be mixed or blended are added in batches. During or after mixing or blending, the homogenous food mass is extruded or discharged in a stream out of an orifice in the mixing cavity. Such mixers or blenders are limited to distributing a concentrated homogenous mass of food material. Generally, the blended material is in the form of a food mass, cluster or high density stream apparatus for forming a homogenous or concentrated food mass and discharging the same through an outlet orifice is generally an unacceptable apparatus or method for controllably distributing granular food material at a selected density onto an article of food.